This is an online writing app that allows you to automatically reference then export into various academic-friendly format. Collaborative editing. Open source as far as I can see.

Fidus Writer is an online collaborative editor especially made for academics who need to use citations and/or formulas. The editor focuses on the content rather than the layout, so that with the same text, you can later on publish it in multiple ways: On a website, as a printed book, or as an ebook. In each case, you can choose from a number of layouts that are adequate for the medium of choice.